KM3NET STATUS AND PERSPECTIVES - JANUARY 5-11, 2020 16TH RENCONTRES DU VIETNAM - QUY NHON MAURO TAIUTI - ON BEHALF OF THE KM3NET COLLABORATION
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KM3NeT
Status and Perspectives
January 5-11, 2020
16th Rencontres du Vietnam – Quy Nhon
Mauro Taiuti - on behalf of the KM3NeT collaboration
Outline
• Preamble
• The Detectors
• The Performances
• First Results
• The Physics Program
• Conclusions
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 2
Motivations & Objectives
Astroparticle
Research
• KM3NeT is the neutrino research infrastructure in the deep
with Cosmics Mediterranean Sea
In the Abyss
Oscillation
• ARCA (off shore Capo Passero, It @ 3500 m depth)
Research
with Cosmics
In the Abyss
• ORCA (off shore Toulon, Fr @2500 m depth)
2475m ORCA 3400m ARCA
• Same collaboration, same technology, two deep sea sites
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 3
Motivations & Objectives
Low Energy Medium Energy High Energy
MeV < Eν < 100 GeV 10 GeV < Eν < 1 TeV Eν > 1 TeV
ν Oscillations Dark matter Cosmic ν
Identification and study
Mass hierarchy Monopoles, Nuclearites of HE neutrino sources
Supernovae Origin and production
mechanism of HE CR
KM3NeT - ORCA KM3NeT -ARCA
+ oceanography, biology, seismology,…
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 4
The KM3NeT Collaboration
• 15 Countries
• 55 Institutes
• >240 Scientists
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 5
The Detectors KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 6
The KM3NeT Telescope Design
• Detection principle Cherenkov radiation induced by charged particles produced
in neutrino interactions
• 6 order of magnitude in ν energy (GeV-PeV )
• All flavour detection
• 3D arrays built with a modular design
• Optical sensor: multi-PMT (DOM)
• Detection units (DU)
• vertical slender strings host 18 DOMs
• 3 Building blocks of 115 DUs each
• DOM and DU spacing optimized for the studied
ν energy range ARCA ORCA
• Power and data distributed by a single Location ItalybackboneFrance
cable with breakouts at DOMs DOM spacing 36 m 9m
• Sea network of submarine cables and DU length Junction 153 m
612 m
Boxes connected to shore via a main e/o cable
• 90 m 23 m
DU spacing
All data to shore
Instrumented mass 2*500 Mton 8 Mton
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 7
The DOM - Digital Optical Module
• 31 x 3” PMTs
• LED & acoustic piezo
inside
ø 17”
• Tiltmeter/compass
• Gbit/s fibre DWDM
• Hybrid white rabbit
• Digital photon counting
• Directional information
• Wide angle of view
• Improved background rejection
• Compact and cost effective design: 1 DOM ≅ 3 ANTARES OMs
(photocathode area)
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 8
The Detection Unit
• 18 DOM integrated on a
LAUNCHER VEHICLE
vertical slender strings
supported by two parallel
Dynema ropes
• Strings arranged on the LOM,
mounted on the anchor and
ready for deployment
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 9
The Seafloor Network
ORCA
ARCA/ORCA ARCA
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 10Event Topologies and Detector
Response
• νµ are the golden channel for neutrino
astronomy
• Deep sea water properties, i.e. long
scattering length allow to achieve very
good angular resolution
Energy resolution Angular resolution
about 0.3 in logEμ about 0.1° (Eν>10 TeV)
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 11Event Topologies and Detector
Response
• Contained shower νe
Energy resolution Angular resolution
about 10% about 2° (Eν>10 TeV)
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 12From Validation to Construction
Prototype DOM deployed at Antares site April 2013
Test of photon counting capabilities and
directional sensitivity of DOM
Eur. Phys. J. C (2014) 74:3056
Prototype DU (three DOMs) deployed in Capo Passero May 2014
Test of DU structure functionality
Test of intra-DOM and inter-DOM
calibration - Eur. Phys. J. C (2016) 76:54
First ARCA DU deployed in Capo Passero December 2015
Muon flux dependence on depth
DU calibration
Trigger implementation
Track reconstruction and MC comparison
(papers in preparation)
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 13A Phased Approach
PHASE BLOCKS PRIMARY DELIVERABLES FUNDS
Proof of feasibility and first science
1 0.2 results Fully funded
24 ARCA + 6 ORCA strings
All flavor neutrino physics and Funding in
astronomy progress
2 2+1
2 x 115 ARCA strings (presently 1/3
1 x 115 ORCA strings available)
Neutrino astronomy including
3 6 Galactic sources Next step
P2O – Long Base Line Protvino-ORCA
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 14The construction is based
on a distributed architecture
KM3NeT Phase-1
Infrastructure
3 Detector sites
2 PMT preparation sites
KM3NeT-HQ 8 DOM integration sites
Amsterdam
3 base module integration sites
4 DU integration sites
Erlangen
3 DU test and preparation
Strasbourg
to deployment sites
Nantes
1 electronic refurbishment center
Bologna
Genova
Marseille The present organization
KM3NeT-Fr
will permit to complete
Bari
Valencia Naples/ the construction of ORCA
Caserta by the end of 2024 and of
Athens
Catania/ ARCA by the end of 2023
LNS (first BB) and beginning
KM3NeT-Gr
Rabat 2026 (second BB)
KM3NeT-It 15
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 15Phase 1 - ARCA
• ARCA-DU1 and ARCA-DU2 deployed December 2015 and May 2016
at Capo Passero, Sicily and worked till April 2017
• ARCA-DU1 operativity resumed in January 2019
• Plenty of data
• Presently the on-shore station is under renovation to host the second
cable power supply
• The seafloor network is scheduled to return operative before
summer 2020 with 6 DUs connected
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 16Phase 1 - ORCA
• First ORCA DU successfully deployed and connected in September
22nd, 2017
• Replacement of the cable during two different sea campaigns in
October 2018 (12th-16th and 22nd-26th)
• Two DUs in operation since
May 17th, 2019
• Four DUs in operation since
July 1st, 2019
• The deployment of two additional
DUs postponed to early 2020 due
to bad weather conditions
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 17The Performances KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 18
DOM Performances
• The DOM design allows the rejection of environmental
background setting a threshold on multiplicity
• The DOM provides also info on the direction of the
detected light
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 19DU Performances
• Events are reconstructed with timing
DOM correlation
• Very low ambiental noise
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 20DU Performances
• Events are reconstructed with timing
DOM correlation
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 21Detector Performances
• KM3NeT-ARCA project goals
• For Eν >10 TeV track events (muons) → Median angular
resolutionTechnical Solutions
• Timing:
• synchronization based on White
Rabbit time distribution protocol
• Orientation:
• Compass installed in each DOM
• Positioning:
• Long Base-Line (LBL) of acoustic transmitters (beacons) and
receivers, located at known positions as provided by NAAPS
(Navigation and Absolute Acoustic Positioning System)
• Piezo-electric Digital Acoustic Receivers (DAR) glued to the glass
sphere of each DOM (used also to monitor the movement of the
DUs)
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 23Positioning System
• The DU shape and the DOM position is known at the level
of few cm!
ARCA-DU1
preliminary
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 24First Results KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 25
ARCA + ORCA Muon Flux Depth
Dependence
Absolute muon flux
Single DOM Aeff=96±4 m2
ORCA: 320 hours
1 string
ARCA: 1269 hours
2 strings
Integrated atmospheric muon flux measured as a function of depth below the sea level
(red points). The systematic errors are displayed as light red shadowed areas.
The Bugaev model of the atmospheric muon flux is drawn with a dashed black line.
ANTARES data are included as blue points for comparison (systematic errors are the
light blue shadowed area).
The depth is expressed in water equivalent (w.e.). Statistical uncertainties are included
and smaller than markers.
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 26Neutrinos in ORCA
Number of events/bin
Likelihood/number of hits
surviving events after
quality track cuts:
Data: 77
ν MC: 67.5
µ MC: 4
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 27Neutrinos in ORCA
• Neutrino candidates with 4 DUs
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 28Sensitivity to Supernovae
• Single DOMs can be used as Supernova
neutrino detector
• Coincidences due to Supernova
neutrinos show a harder distribution
than 40K but softer than muons
• Best sensitivity for PMT coincidence
level 6-10
• Combined sensitivity : 5σ for
ARCA+ORCA for 27M☉ at a
distance 25kpc
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 29Physics Program KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 30
ARCA Sensitivity to Diffuse
Neutrino Flux
Monte Carlo studies
• Track channel: analysis for up-
going events based on max.
likelihood
• Pre-Cuts on θzen >80°, Λ
(reconstruction quality
parameter), Nhit (number of
hits → parameter related to
the muon energy)
• Cascade channel: contained
events
• Vertex cut: cut on position of
reconstructed vertex (zARCA Sensitivity to Diffuse Flux
from the Galactic Plane
• ARCA sensitivity to a flux from a region of the Galactic Plane near the
Galactic Center. Neutrino flux estimate based on a radially-
dependent cosmic-ray transport model
Discovery at 5σ significance in about 5 years
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 32ARCA Sensitivity to Point-like
Galactic Sources
• HE gamma emission observed by HESS in
SNRs
• Neutrino spectra predicted using gamma
spectra
• ¶ S.R. Kelner, et al., PRD 74 (2006) 034018
• § F.L. Villante and F. Vissani, PRD 78 (2008) 103007
• Hypotheses: 100% hadronic emission and
transparent source
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 33ARCA Sensitivity to Point-like
Sources
• ARCA can survey almost the
whole sky with a discovery
potential @ 5σ about one
order of magnitude better
than IceCube for equivalent
exposure
Φ νµ ∝ E-2
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 34Neutrino Mass Hierarchy with ORCA
• A "free beam" of known composition (νe, νμ)
• Wide range of baselines and energies
• Oscillation pattern distorted by Earth matter
effects
maximum difference IH vs NH for resonance in
Earth mantle: θ=130° (7645 km) and Eν = 7 GeV
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 35ORCA Sensitivity to Mass Hierarchy
• 3σ for most of the parameter space after 3 years
• much better if NH and 2-nd Octant of θ23
3 yrs
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 36ORCA Measurement of ∆m232 and
sin2θ23
• Achieve 2-3% precision in ∆m232 and 4-10% in sin2θ23
• Competitive with NOvA and T2K projected sensitivity in 2020
• T2K 7.8 1021 p.o.t.
Normal Hierarchy
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 37Additional ORCA Physics Topics
• Unitarity of PMNS matrix
• Exotic physics
• sterile neutrino, non-standard interactions
• Dark Matter
• Earth tomography
• Low energy neutrino astronomy
• Transient phenomena
• Earth and Sea Science
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 38Multi-messenger Program
• Alerts:
• Online reconstruction
• Dedicated triggers for events of interest
• Distribute alerts via the GCN network
• The optimization of the dedicated trigger for Galactic Core Collapse
Super Novae has already begun
• Follow up EM / GW alerts
• Offline correlation with catalogs (GRBs, AGNs, XRBs,
SNs, FRBs, …)
• Synergies and MoUs are in the process of being formed.
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 39Summary
• Several lessons learned
• The measured detectors performances respect the design
parameters
• We are confidently proceeding with the integration of the
next DUs
• KM3NeT is going to become a key infrastructure for
neutrino astronomy in the next decade
KM3NeT - M.Taiuti - 16th Rencontres du Vietnam 40Thank you!
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